Hydroair union nut and tail piece, fits all their Genesis and perseus range of air blowers.
Hydroair Genesis G50-2AN-S 500W bath air blower - Pneumatic air switch on/off control, non heated model.
Hydroair Genesis G50-2HN-S 500W heated spa & bath air blower, model has 250W integral heater and is electronically controlled by a spa control system to turn on/off.